1. Field of the Invention
The invention pertains to a steam generating plant of the type having a steam generator including a combustor; a set of steam turbines; a condensate circuit connected to the steam generator; a flue gas line connected to the combustor; an air feed line for supplying combustion air to the combustor; and an air pre-heater wherein the combustion air is pre-heated by the flue gas.
2. Description of the Related Art
By burning fossil fuels, these types of steam generating plants generate the CO2 which is held responsible for the destruction of the ozone layer of the atmosphere. Industry and various universities are therefore conducting joint research projects to develop ways of separating CO2 from the flue gas produced in the power generation industry.
These joint development projects include the conversion of CO with H2O to CO2 and H2, followed by separation of the CO2 in an integrated gasification combined cycle (IGCC process), and the combustion of fossil fuel with pure oxygen and subsequent separation of the CO2 (oxy-fuel process). According to current estimates, it will take some time, e.g., about 10-20 years, before it will be possible to realize the construction of new steam generating plants based on the oxy-fuel process, and even then it will be associated with high investment costs.
It could be much more favorable to retrofit existing, conventionally fired power plants, because the investments would be much lower. Because of the CO2 separations associated with combustion with pure oxygen, only power plant blocks of the higher power output ranges of 100-300 MW can be considered for an oxy-fuel retrofit. This is true not only because of the cost but also because of the size of the compressor units which must be used.